I answer that, email is a very different beast than HTTP. 1. If we were to transition to my hypothetical Email2, that doesn't mean it's all or nothing. The tra

I answer that, email is a very different beast than HTTP. 1. If we were to transition to my hypothetical Email2, that doesn't mean it's all or nothing. The transition to HTTPS, does not mean that HTTP no longer is readable. Similarly, the transition would not mean classic emails are automatically unreadable either - but there's a strong incentive for corporations relying on it to fix it. Hypothetically, there would be an MX2, and an MX record. MX would be the fallback for if MX2 sending is not available. So if an out-of-date client from 10 years ago sends an email, it finds the MX record and sends it, no problem. However, the receiver expecting MX2, automatically classifies the email as Insecure and Junk. Meanwhile, an MX2-enabled sender could identify the MX record for a website that does not support MX2 yet, and still deliver the message. 2. Email is not the same as a device. Most emails are sent from an email server with hundreds of inboxes. Take Google and Microsoft - they are 40% of global email traffic. Add Yahoo, GoDaddy, and the other big names, and you're well on the way. Unlike HTTP, the transition may actually be much quicker, because self-hosting email is not very popular (and those that do, are using commercial or open-source packages which could easily add support).